COMPLETE INDEPENDENCE convince any considerable body of professional mathematicians that symbolic logic might be worth their serious attention. One staunch hater of symbolic logic may be mentioned - Cantor, whose work on the infinite will be noticed in the concluding chapter. By one of those little ironies which make mathematical history such amusing reading for the open-minded, symbolic logic was to play an important part in the drastic criticism of Cantor's work that caused its author to lose faith hi himself and his theory. Boole did not long survive the production of his masterpiece. The year after its publication, still subconsciously striving for the social respectability that he once thought a knowledge of Greek could confer, he married Mary Everest, niece of the Pro- fessor of Greek in Queen's College. His wife became his devoted disciple. After her husband's death, Mary Boole applied some of the ideas which she had acquired from him to rationalizing and humanizing the education of young children. In her pamph- let. Book's Psychology, Mary Boole records an interesting speculation of Boole's which readers of The Laws of Thought will recognize as hi keeping with the unexpressed but implied personal philosophy in certain sections. Boole told his wife that hi 1832, when he was about seventeen, it 'flashed upon' him as he was walking across a field that besides the knowledge gained from direct observation, man derives knowledge from some source undefinable and invisible - which Mary Boole calls 'the unconscious'. It will be interesting (in a later chapter) to hear Poincare expressing a similar opinion regarding the genesis of mathematical 'inspirations' in the 'subconscious mind*. Any- how, Boole was inspired, if ever a mortal was, when he wrote The Law of Thought. Boole died, honoured and with a fast-growing fame, on 8 December 1864, in the fiftieth year of his age. His premature death was due to pneumonia contracted after faithfully keeping a lecture engagement when he was soaked to the skin. He fully realized that he had done great work.